This how to was done on my '06 ram 1500, but i believe the wiring is the same on all rams. To start you will need the following:
Short phillips screw driver
Wire strippers
Soldering iron, solder
LED's rated for 12V power
Hot glue gun, or electrical tape
Drill, and bits varying on what size LED you use
To start, remove the center dash piece by unscrewing the two screws found at the bottom 06 and up only:
Then just pull firmly to remove the cover. You will need to unplug all of the plugs such as the A/C control panel, cig lighter etc. and set the whole cover aside. Remove the top cubby buy unscrewing all 6 screws, pull the radio out slightly, the cubby will come out following, push the radio back in, and take the cubby and dash cover to your working area. Next you will want to stip and solder all the LEDs together. Then drill a hole in the top of the two cubbies, insert the LED and either tape over it to hold it in place, or use hot glue.
Next will come the cup holder LEDs. For this I used two lights, a piece of cardboard, and tape. Just poke two holes in the cardboard, insert the LEDs, tape them, and then tape it into the slot above the cup holders.
Now just pull the wire harness not being used with the black and white wire, and tap into it either by cut and splice with a cap so you can remove, or a clip, or even soldering for a more permanent set up. The white wire is positive, black negative, so wire accordingly.
Now just put everything back together in reverse order, and your done!
These are the LEDs I used, picked them up at advanced auto parts
Enjoy your new lights!